I've just realized that help message in a subcommand didn't show one
in the parent command. Since the option parser understands the parent,
display code should do the same. For example, `perf ftrace latency -h`
should show options in the `perf ftrace` command too.
Before:
$ perf ftrace latency -h
Usage: perf ftrace [<options>] [<command>]
or: perf ftrace [<options>] -- [<command>] [<options>]
or: perf ftrace {trace|latency} [<options>] [<command>]
or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>]
-b, --use-bpf Use BPF to measure function latency
-n, --use-nsec Use nano-second histogram
-T, --trace-funcs <func>
Show latency of given function
After:
$ perf ftrace latency -h
Usage: perf ftrace [<options>] [<command>]
or: perf ftrace [<options>] -- [<command>] [<options>]
or: perf ftrace {trace|latency} [<options>] [<command>]
or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>]
-a, --all-cpus System-wide collection from all CPUs
-b, --use-bpf Use BPF to measure function latency
-C, --cpu <cpu> List of cpus to monitor
-n, --use-nsec Use nano-second histogram
-p, --pid <pid> Trace on existing process id
-T, --trace-funcs <func>
Show latency of given function
-v, --verbose Be more verbose
--tid <tid> Trace on existing thread id (exclusive to --pid)
Signed-off-by: Namhyung Kim <[email protected]>
---
*v2: remove goto and add comments (Ian)
tools/lib/subcmd/parse-options.c | 36 +++++++++++++++++++++-----------
1 file changed, 24 insertions(+), 12 deletions(-)
diff --git a/tools/lib/subcmd/parse-options.c b/tools/lib/subcmd/parse-options.c
index 9fa75943f2ed..eb896d30545b 100644
--- a/tools/lib/subcmd/parse-options.c
+++ b/tools/lib/subcmd/parse-options.c
@@ -806,18 +806,30 @@ static int option__cmp(const void *va, const void *vb)
static struct option *options__order(const struct option *opts)
{
- int nr_opts = 0, nr_group = 0, len;
- const struct option *o = opts;
- struct option *opt, *ordered, *group;
-
- for (o = opts; o->type != OPTION_END; o++)
- ++nr_opts;
-
- len = sizeof(*o) * (nr_opts + 1);
- ordered = malloc(len);
- if (!ordered)
- goto out;
- memcpy(ordered, opts, len);
+ int nr_opts = 0, nr_group = 0, nr_parent = 0, len;
+ const struct option *o, *p = opts;
+ struct option *opt, *ordered = NULL, *group;
+
+ /* flatten the options that have parents */
+ for (p = opts; p != NULL; p = o->parent) {
+ for (o = p; o->type != OPTION_END; o++)
+ ++nr_opts;
+
+ /*
+ * the length is given by the number of options plus a null
+ * terminator for the last loop iteration.
+ */
+ len = sizeof(*o) * (nr_opts + !o->parent);
+ group = realloc(ordered, len);
+ if (!group)
+ goto out;
+ ordered = group;
+ memcpy(&ordered[nr_parent], p, sizeof(*o) * (nr_opts - nr_parent));
+
+ nr_parent = nr_opts;
+ }
+ /* copy the last OPTION_END */
+ memcpy(&ordered[nr_opts], o, sizeof(*o));
/* sort each option group individually */
for (opt = group = ordered; opt->type != OPTION_END; opt++) {
--
2.44.0.769.g3c40516874-goog
On Mon, Apr 29, 2024 at 4:37 PM Namhyung Kim <[email protected]> wrote:
>
> I've just realized that help message in a subcommand didn't show one
> in the parent command. Since the option parser understands the parent,
> display code should do the same. For example, `perf ftrace latency -h`
> should show options in the `perf ftrace` command too.
>
> Before:
>
> $ perf ftrace latency -h
>
> Usage: perf ftrace [<options>] [<command>]
> or: perf ftrace [<options>] -- [<command>] [<options>]
> or: perf ftrace {trace|latency} [<options>] [<command>]
> or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>]
>
> -b, --use-bpf Use BPF to measure function latency
> -n, --use-nsec Use nano-second histogram
> -T, --trace-funcs <func>
> Show latency of given function
>
> After:
>
> $ perf ftrace latency -h
>
> Usage: perf ftrace [<options>] [<command>]
> or: perf ftrace [<options>] -- [<command>] [<options>]
> or: perf ftrace {trace|latency} [<options>] [<command>]
> or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>]
>
> -a, --all-cpus System-wide collection from all CPUs
> -b, --use-bpf Use BPF to measure function latency
> -C, --cpu <cpu> List of cpus to monitor
> -n, --use-nsec Use nano-second histogram
> -p, --pid <pid> Trace on existing process id
> -T, --trace-funcs <func>
> Show latency of given function
> -v, --verbose Be more verbose
> --tid <tid> Trace on existing thread id (exclusive to --pid)
>
> Signed-off-by: Namhyung Kim <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Thanks,
Ian
> ---
> *v2: remove goto and add comments (Ian)
>
> tools/lib/subcmd/parse-options.c | 36 +++++++++++++++++++++-----------
> 1 file changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/tools/lib/subcmd/parse-options.c b/tools/lib/subcmd/parse-options.c
> index 9fa75943f2ed..eb896d30545b 100644
> --- a/tools/lib/subcmd/parse-options.c
> +++ b/tools/lib/subcmd/parse-options.c
> @@ -806,18 +806,30 @@ static int option__cmp(const void *va, const void *vb)
>
> static struct option *options__order(const struct option *opts)
> {
> - int nr_opts = 0, nr_group = 0, len;
> - const struct option *o = opts;
> - struct option *opt, *ordered, *group;
> -
> - for (o = opts; o->type != OPTION_END; o++)
> - ++nr_opts;
> -
> - len = sizeof(*o) * (nr_opts + 1);
> - ordered = malloc(len);
> - if (!ordered)
> - goto out;
> - memcpy(ordered, opts, len);
> + int nr_opts = 0, nr_group = 0, nr_parent = 0, len;
> + const struct option *o, *p = opts;
> + struct option *opt, *ordered = NULL, *group;
> +
> + /* flatten the options that have parents */
> + for (p = opts; p != NULL; p = o->parent) {
> + for (o = p; o->type != OPTION_END; o++)
> + ++nr_opts;
> +
> + /*
> + * the length is given by the number of options plus a null
> + * terminator for the last loop iteration.
> + */
> + len = sizeof(*o) * (nr_opts + !o->parent);
> + group = realloc(ordered, len);
> + if (!group)
> + goto out;
> + ordered = group;
> + memcpy(&ordered[nr_parent], p, sizeof(*o) * (nr_opts - nr_parent));
> +
> + nr_parent = nr_opts;
> + }
> + /* copy the last OPTION_END */
> + memcpy(&ordered[nr_opts], o, sizeof(*o));
>
> /* sort each option group individually */
> for (opt = group = ordered; opt->type != OPTION_END; opt++) {
> --
> 2.44.0.769.g3c40516874-goog
>